1. The polarity checklist:
_____ polar bonds
_____ asymmetric arrangement
Review: Are the following substances polar or non-polar? Justify your response. XeF2 O3 SCl4

2. XeF2 Click Me
O Click Me
SCl4 Click Me

3. Other Bond Properties 1. Bond Order, see ozone . . . 2. Bond Length
Distance between the nuclei of the two atoms
For single bonds: larger atoms results in longer bonds
17 p+
5 p+
9 p+
5 p+

4. Other Bond Properties 1. Bond Order, see ozone . . . 2. Bond Length
Distance between the nuclei of the two atoms
For single bonds: larger atoms results in longer bonds
For double / triple bonds: higher bond order = shorter bond

5. Other Bond Properties
Bond Order and Bond Length are not always as easy to analyze as they appear …
Which ion has the longer bonds, NO2- or NO3-?
(resonance IS a factor with bond order/length)

6. Other Bond Properties 3. Bond Dissociation Energy
The energy required to break a bond (measured while reactants and products are in the gas phase)
Larger bond length = lower bond dissoc. energy
WHY? It’s all about Coulomb’s Law …
Stronger attraction will exist with higher charges and smaller distances.

8. Sample AP Chem question